This species was discussed and well illustrated for Taiwan by Chaw and Peng (J. Taiwan Mus. 40(2): 57-59. 1987); its seeds were illustrated in detail by Chaw and Sivarajan (Bot. Bull. Acad. Sin., n.s., 30: 18, f. 10-11. 1989).

These plants were treated by W. C. Ko (in FRPS 71(2): 208. 1999) as Spermacoce stricta Linnaeus f. (Borreria stricta (Linnaeus f.) G. Meyer), following previous usage by various authors (see discussion in Chaw & Peng, loc. cit.), but as detailed by Sivarajan and Nair (Taxon 35: 363-369. 1986) the identity of the name S. stricta is not at all clear and very likely actually applies to a species of Hedyotis. W. C. Ko (loc. cit.) described the seeds of this species as transversely striate/grooved and with one end mucronate, another end obtuse; however, the seeds are smooth with both ends obtuse to rounded on all specimens studied, and as described by Dessein (Syst. Stud. Spermacoceae (Ph.D. Diss.), University of Leuven, Belgium, 1-403. 2003).

Sivarajan and Nair (loc. cit.) separated the Indian plants treated in "Spermacoce stricta" into two species, S. pusilla and a newly described species, S. ramanii Sivarajan & R. V. Nair. They gave the range of S. ramanii only as India, although they considered several additional names synonymous, with a consequent tacit expansion of its range to Thailand, New Guinea, and Java. Dessein (loc. cit.) discussed the separation of these and concluded that there appear to be two species in India but only one variable species in Africa; he found the contrasting character states in all possible combinations in Africa and did not adopt the name S. ramanii for any African plants. The Chinese plants seen appear to comprise one well-delimited species and are here all treated as S. pusilla; however, as with the African plants, several of the features that Sivarajan and Nair used to separate S. ramanii, which are largely vegetative characters, are found on some Chinese plants in various combinations with other features. The name S. ramanii is, therefore, not synonymized nor used here for any Chinese plants; it has been cited for China by the Kew Rubiaceae checklist (Govaerts et al., World Checkl. Rubiaceae; http://www.kew.org/wcsp/ rubiaceae/; accessed on 15 Sep 2010) but without documentation of the report.